Locomotive boiler



Patented Nov. 9, 1926.

rara

realise LOCOMOTIVE BOILER.

Application filed December 12, 1924. Serial No, 755,562.

rlhis invention relates to boilers and more particularly to a steam dome arrangement tor use in conjunction with locomotive type boilers.

It has been found that where the maximum overall height or a boiler is limited, as in railway practice, that the use or the ordinary type ot steam dome results in restricting the steam space and the water surface, which may be conveniently termed the steam disengaging surface so that the throttle valve, which is located in the steam dome, may entrain a considerable quantity of water due to violent disengaging of the steam, the disadvantages of which are wellknown. It is an object of this invention to provide in a locomotive type boiler, an improved steam dome construction which pro-l vides an increased steam disengaging surface, an increased steam space and which may be constructed without the use oi stays.

In the accompanying drawings and Yfollowing specification there is disclosed by way of example, only, a single embodiment of the invention with the understanding that various changes may be made in the form, size, proport-ion and arrangement of the various parts by those Vskilled in the art Without departing from the spirit of the invention as more particularly pointed out in the appended claims.

In said drawings,

Figure l is a partial longitudinal vertical section through a steam boiler constructed according to this invention, and

Figure 2 is a transverse vertical section on line 2-2 of Figure l.

In modern railway practice it-is necessary to provide locomotives of great power and in order to supply suilcient steam, boilers oi' large steaming capacity are necessary. The size of the boiler shells which must be cylindrical, in good practice, to eliminate staying is limited by two 4factors, iirst, the height of the ruiming gear and trame, and second, the height of tunnels, bridges, viaducts, etc., beneath which the locomotives must pass. It is the usual practice to provide at the top of the main barrel-sheet steam dome within which is arranged the throttle valve leading to the dry pipe. rlChe purpose ot this dome is, ot course, to maintain the throttle valve at as great a distance as possible above the surface oi: the water in the boiler to prevent entraining water with the steam. The top of the dome is therefore made as high as allowable by the second limitation mentioned above, but since the dome is usually of small size and the main barrelsheet of substantially the same diameter as the remaining portions of the barrel, the steam space above the water is quite limf ited, in Vfact in some of the largest locomotives the water level is only about nine inches below the inside of the top of the barrel-sheet. This materially reduces the area of the steam disengaging surface resulting in violent boiling, priming `and foaming and increasing the tendency to entrain water into the throttle valve. The present invention. accomplishes the desired results by i providing an enlarged, main barrel-sheet, circular' in cross-section, tangential at the bottom with the remaining barrel-sheets and reaching at the top to the maximum yheight permissible 'for clearance in tunnels, etc., as mentioned.

Referring to the drawings, l() indicates the forward portion of the' barrel of a locomotive boiler, connected by means oi' the main barrel-sheet ll with the lire-box section l2 here shown as of the Belpaire type. The forward portion ot the barrel l is circular in cross-section as is usual and thereiore the forward end 13 of the portion 1l is also circular to be readily iitted thereto. The enlarged central portion of the main barrel-sheet 1l is circular in cross-section as best shown in Figure 2 and forms, at the bottom, a substantially straight surface with the section l() and the lower portion of the fire-box section l2 to which it is joined at the section 'le by a lapjoint. The section l1 is however eccentrically located in respect to the other barrel sections owing to its larger diameter but the bottom is'lile a standard boiler. lilith this construction the central line of the boiler will be indi-A cated by the dot and dash line shown in Figure l. Connecting the large central portion ot the main barrel-sheet l1 and the smaller circle of the section 13 is the tapered section l always circular in cross-section on section lines at right angles to the main central line of the boiler to eliminate the need or staying. The reduced rear section .le is connected to the main portion by a similar tapered section 16 and the portion le is shaped to conform to the forward end ot the tire-boi; construction which in the lll) Belpaire type disclosed is provided with the hips 17. In case the boiler is used with a wagon-top type of lire-box the portion 14 will be circular in cross-section owing; to the circular rooll on this type of tire-box. As in the section 15, the section 1G is so shaped as to be circular in cross-section at all sectionsarranged at right angles to the longitudinal center line 'of the boiler.

In order that the main barrel-sheet may be shaped asshown it is necessary to form it in two parts which can each be readily fitted in a press i'or shaping, the two parts being joined by butt joints 18 along the sides. rIhe opening 19 in the top of the main barrel-sheet, which corresponds to the opening in the usual dome, is reinforced by the internal ring member 20. The joints 18 of the barrel-sheet are reinforced by the inner and outer plates 21 and 22.

It will be seen that this construction provides in effect a combination barrelsheet and steam dome which is equivalent to ex.

thus provided Without increasing the overall height of the boiler.

Having thus described the invention, what is claimed asnew and desired to be secured by U, S. Letters Patent is:

1. In a locomotive type boiler, a shell comprising,` two end sections, a circular section intermediate and joining said end sections being of greater cross-sectional area than said end sections and joined to the end sections so that the lowest portions of all sections'form a substantially straight surface, whereby increased steam space is provided.

2. In a locomotive type boiler, in, combination, a iire-boX section, a barrel section, a combination main barrelsheet and dome section interposed between said first mentioned sections, said combination main barrel-sheet and -dome section being larger in diameter than the barrel and tire-boi; sections7 tangential thereto at the bottom and having' reduced ends for connection to adjacent sections, to thus provide increased steam space and steam disengzugingsur face.

In testimony whereof I hereunto aiii; my signature.

IVILLIAM F. KIESEL, Jn. 

